Traditionally ploughs were designed to make several passes over the same piece of ground and/or designed to invert the soil before the seed and/or fertiliser was deposited by the soil surface. These known methods resulted in destruction of the soil structure which is detrimental to new growth resulting from germination of a newly planted seed. A further disadvantage is moisture loss.
The plough described in Australian Patent 528237 addressed the above issues. This plough had a digging point to undertake deep tillage, that is fracturing of the soil as opposed to destroying the soil structure. Although the plough described in the above Australian patent addressed issues in respect of maintaining moisture and soil structure, a disadvantage thereof was placement of the seed and preparation of the seed bed.
It is not uncommon for tine seeding machinery and their attachments to experience difficulty in penetrating soil deeply while at the same time maintaining accurate placement of the seed and fertiliser. Due to the uneven ground surface over which ploughs pass, seeding depth was controlled by widely spaced ground rules. A disadvantage of these ploughs was that seeding depth could not be accurately maintained, often resulting in the seed and fertiliser being placed together on a hard soil barrier causing poor seed germination, loss of plant vigour, low yields, poor water penetration, water logging, fertiliser toxicity and a greater incidence of plant disease.
The above problems were addressed by the ploughs described in Australian Patents 541415, 640025, 675376 and 2007202357, as well as Australian Patent Application 2011201476.
A disadvantage of the above described ploughs is that construction of the plough and replacement of wear parts, such as the digging blades and closing tools, is difficult. A still further disadvantage is that the use of power tools is prevented or at least inhibited. This greatly increased the time and therefore cost of construction of the ploughs while making it difficult and therefore time consuming to service.